Please follow these instructions to setup single sing-on integration for your VanillaForums. We don't cover VanillaForums integration in details as this information could be found on their official website.

• Install VanillaForums on the same domain where you have Subrion CMS installed.
• Install VanillaForums jsConnect plugin: http://vanillaforums.org/addon/jsconnect-plugin
• Open VanillaForums dashboard and click Plugins, edit jsConnect plugin.
• Add new connection as follows:
  1. Click Generate Client ID and Secret
  2. Site Name = whatever you wish
  3. Authenticate Url = (insert your full URL to subrion cms installation)/login/read.json
• Save Changes
• Go to Users > Registration and change 'Change the way that new users register with the site' to 'Connect'
• Install Subrion plugin VanillaForums Signle Sign-On
• Go to Subrion Admin Panel -> Configuration -> Miscellaneous
• Find the section related to VanillaForums and insert the key & Secret you generated in VanillaForums dashboard, Save Changes
• Create a new page with External Content and place it in the menu. It should be a full URL to your forums homepage.